...and mythology. I think Odin, Thor, Frey, et al, would place them firmly in the minus column. Polyphemus is also generally not the sort to meet in a dark alley. Numerous giants are mentioned in the Old Testament, all of bad disposition. Finally, in a blend of literature and mythology, there is Cthulhu and his lot, who make all the rest look like angels in comparison.

On the plus side (again from literature), there is Henry_Pym, aka 'Giant Man'. Definitely a good guy, but a 9.9 on the superhero 'Lame Scale'...